Over the past several years, the use of symmetrical AC power has gained a foothold in some industries that are dependent on the field of power quality, the part of the electrical power industry that deals with the quality of power as it affects the performance of sensitive electronics. Conventional AC power, as it is presently being used, requires that at least one of the circuit wires be grounded as AC power is distributed to single-phase loads. In some cases, the frame or chassis of the load is used as a circuit conductor, similarly to how automobiles are typically wired, the chassis being not only used as a ground, but also a conductor through which current flows, to facilitate the operation of various electrical apparatuses in the vehicle. In similar situations, where a generator is used to power electronics, an analogous method of power distribution is used. One of the circuit wires is either grounded or is absent entirely in lieu of using the chassis or frame of the load as a circuit conductor. Consequently, reactive load currents flow through the frame or chassis. These currents often cause sensitive electronics to malfunction or to work improperly. One solution to the problem would be to install a symmetrical power transformer of the type described below and in the parent application (Ser. No. 08/848,123; "the parent application") on the output of the generator, thus placing the grounding reference for the system at a point midway between the two "hot" conductors of the circuit and thusly balancing out or nulling reactive load currents.
The major drawback to this type of power system configuration is the additional weight and expense of adding a transformer to a generator's output. If for example, such a generator/transformer combination were to be connected to sensitive electronic equipment installed on an airplane, the weight and space requirements could pose difficult problems to overcome for aircraft designers.